Graded Performance: Rihanna and Emeli Sande on "The X Factor" UK Finale

Breakout star of 2012 Emeli Sande and pop staple Rihanna took to the stage to perform for the finale of The X Factor. Emeli performed her newest single, "Clown" while Rihanna gave the questionable "Diamonds" a rest to perform stand out ballad "Stay" and her biggest single to date, "We Found Love". How did each act stand out? Let's see...
Emeli Sande:
What I appreciate about Emeli is that she knows she has the voice, but she approaches her live performances with as much caution as possible. However this was not the case with "Clown". You can tell that the song is very personal to her so she allowed herself to be a bit more vunerable. I will say this, there were points in the performance where she didn't have to hold the notes. She looked very lovely by the way.  
Grade:A- Rihanna:
This may just be her best era (in terms of performances) to date. Rihanna decided to sing both of her songs sans back track and did very well, rarely missing a note. I would have liked a male (maybe one of the finalists) to do the male parts of the song to give it the effect the album version does, but I'm not complaining. Also there was that one instance near the end of "Stay" when she tried to hold the note and fell a bit flat but oh well. "We Found Love" was a different story, she got a bit too excited and sounded a bit off and that yelling at the end (no Rihanna,no) but I loved the energy. Grade:B